Heretofore, it has been known that light propagates in the atmosphere, light can transmit material information in a wide spectrum extending from ultraviolet to infrared, and light is a probe capable of imaging a material even in the atmosphere or water which is different from an electron microscope, and an atom force microscope.
It is recognized that such imaging by the use of light is an extremely important technology in also a field of bioscience or the like wherein an observation of, for example, a live cell in a subwavelength level is required.
However, there is such a problem that the limit of resolution due to wave properties of light in imaging wherein a conventional light is used. Namely, the resolution of an image by means of light is in a limit up to a size of wavelength order (several 100 nm) at the most because of the diffraction phenomena of light.
As described above, it is difficult to obtain a spatial resolution exceeding wavelength order by means of a usual microscopical technique. Particularly, a near-field scanning optical microscopy (NSOM), which requires a certain period of time for probe scanning in order to image fine structural information of a submicron wavelength order beard by photons existing locally in the vicinities of the surface of a material body which is concerned with optical near-field, is necessary (see non-patent literary document 1).
A near-field scanning optical microscopy (NSOM) is developed absolutely to perform imaging and analysis due to probe scanning of optical near-field distribution. Consequently, the NSOM is not suitable for the use of the transfer of such information and applying a parallel processing therefor.
Namely, a NSOM has been used heretofore as a device for imaging fine structural information of a subwavelength order, but not a manner for transmitting a near-field image of a subwavelength has been proposed, and thus, the provision of such manner has been strongly desired.
Incidentally, such theoretical provision that a metal thin film having a thickness of several 10 nm functions as a lens having very high resolution has been made in recent years (see non-patent literary document 2). Effectiveness of the theoretical provision is confirmed more recently as a result of experiments (see non-patent literary document 3).
However, the manners disclosed in the non-patent literary documents 2 and 3 relate to a method of image formation by using an extremely thin metal film having a thickness of around several 10 nm. Accordingly, there are such problems that restrictions for an operating frequency, a film thickness condition of the metal film and the like are extremely severe, so that there are many technical difficulties in the actual application of lithography and the like; and further that an out-of-focus image is unavoidable due to the loss of a metal.
On one hand, such a manner that a metallic nanowire is used to transmit a light wave as a wave of electron has been proposed (see a non-patent literary document 4). However, such a problem that there are many technical difficulties in the actual application of lithography in also this manner has been pointed out.    Non-patent literary document 1: S. Kawata et al. ed. “Nano-Optics”, Springer series in optical science (2002)    Non-patent literary document 2: J. B. Pendry, Phys. Rev. Lett. 85, 3966 (2000)    Non-patent literary document 3: N. Fang, et al. Science, 308, 534 (2005)    Non-patent literary document 4: J. Takahara, et al. Opt. Lett. 22, 475 (1997)